1. Field of the Invention
This invention relates to improved construction of an architectural covering for windows, and in particular to a vertical or horizontal blind with individual, narrow strips of sheer material and a vane having a strip element disposed therein.
2. Description of the Related Art
In many window or see-through door applications, it is desirable to control the amount of light admitted through the window or see-through door. For instance on bright sunny days in warm climates, the sun is too strong (and too hot) for comfortable working in offices, as well as being damaging to interior furnishings that may fade or become brittle. Typically, blinds are fitted, consisting of multiple slats of opaque material that can be individually rotated, in a coordinated manner, to block all or part of the light. When such slats are arrayed horizontally, the assembly is commonly called a xe2x80x9cvenetianxe2x80x9d blind.
In large windows or doors, venetian blinds are difficult to raise completely, when needed for unobstructed viewing or to clean the glass behind. So, often a variant called xe2x80x9cvertical blindsxe2x80x9d is fitted, in which rotatable slats are hung vertically from their ends on a traverse mechanism with individual, coordinated rotating hangers. Vertical blinds have been most often used in commercial settings, where large windows are more common. In residential use, only patio doors and the like have commonly used these blinds.
Known vertical blinds commonly comprise elongated strips or slats of opaque material suspended vertically from an overhead traverse mechanism provided with individual, rotatable hangers. Some vertical blind products combine a sheer fabric with the rotatable, opaque vertical slats to provide diffusion of the light entering between the opaque slats, as well as adding privacy as a result of reduction in the clarity of view from the bright exterior into the interior of the building.
Examples of such combination vertical blinds are disclosed in U.S. Pat. No. 3,844,334 to Hyman and U.S. Pat. No. 5,638,880 to Colson et al. In Colson et al., the slats are integrated as stiffened fabric vanes permanently attached onto the expanse of covering sheer fabric. Tachikawa Company of Japan offers a vertical blind in which alternating vanes are sheer and opaque, but the hangers for the sheer vanes lack driven rotators, so that the sheer vanes tend to remain in planar alignment between adjacent opaque vanes when the latter are rotated toward their view-through position. This product lacks the aesthetically-preferred appearance of a continuous, billowed curtain, and gapping between the sheers and opaques is a problem because the sheers are free to rotate, though not forced to do so.
Even in smaller windows, where horizontal shading is practical, there has been a move toward light-diffusing systems. Translucent cellular shades and fabric venetian blinds have been devised using light-filtering materials to give light-diffusing properties to the window coverings. Of these, the fabric venetian blinds also present a sheer fabric covering that partly obscures the interior of a room from outside view, even when the major light-control elements are positioned for open view-through. This is a desirable feature for vertical blinds, too, and has been implemented in two ways: layering of a sheer curtain over a conventional rigid-vane vertical blind; and integrating the slats as stiffened fabric vanes permanently attached onto the expanse of the covering sheer.
The inventors of the present invention have recognized that a disadvantage of known opaque-with-sheer vertical blinds is that they use a large expanse of fragile sheer fabric to cover the entire opening. This requires a high degree of costly precision in fabric quality, handling, and cleaning to assure the delicate fabric remains free of visible flaws and damage throughout. The manufacturing equipment must be very large and costly (typically handling goods 90 to 150 inches in width), adding immensely to the final product cost and limiting the variety of colors and styles that can be produced. Waste in fabricating finished shades from such goods to fit various window sizes is significant (typically over 20% of raw goods, even with carefully optimized fitting). Installation, and even shipping, is extremely awkward with such large delicate sheers, and washing is almost impossible. Should one spot on the product become soiled or damaged, the entire product becomes waste. Still, consumers readily pay this price to achieve the soft, light-diffusing privacy and light control provided by such sheers with rotatable vanes.
In one embodiment of the invention, the architectural covering comprises a vertical or horizontal blind including an opaque strip or vane and a covering sheer strip, wherein the vanes are not expanded by any bowing or resilience. Each vane comprises an integrated composite of a relatively opaque portion and a laterally adjacent and relatively translucent portion having an upper end that is remote from its associated relatively opaque portion. The upper end is adapted to be secured to at least one of either the next adjacent hanger (typically carrying the next adjacent vane) or the free end of the relatively opaque portion of the next adjacent vane when such vane is installed in a window opening. This embodiment of the invention is especially useful for smaller windows and very flaccid sheers if the opaque strips are relatively heavy and stiff.
In another embodiment of the invention, an improved blind is disclosed for use primarily over vertically-glazed windows and doorways comprising a plurality of separate composite strips, wherein each composite strip is manufactured as a flat, rollable overlay assembly of strips. At least one of the strips could be transversely elastically bowed and attached along its free edge to another strip, forming a substantially rigid closed-perimeter element with an expanded cross-section for torsional and flexural strength.
The expanding of the section may be accomplished in a variety of ways. One way is by providing one strip having a transverse width greater than that of the one to which it joins, and by making the former strip resilient to bowing so as to create tension in the latter strip when the two are joined edge-to-edge after removal from a rolled to a straight condition. Another way the bowing may be accomplished is by inserting a separate resilient folded strip into the closed-perimeter element formed by edge-joining of strips in the basic composite, whereby the resilient strip is fitted into and through a substantial part of the length of the composite, after the composite is removed from a roll into a straight condition. Yet another way the bowing may be accomplished is by providing a resilient insert having a xe2x80x9cVxe2x80x9d, xe2x80x9cCxe2x80x9d or xe2x80x9cS section form (or the like) that may be inserted into the closed-perimeter composite before rolling, whereby the resilient insert can assume a flat transverse form, but return elastically to the V, C, or S (or the like) when removed from the roll.
In one embodiment, each composite strip comprises at least a sheer or translucent portion and a relatively opaque portion; the two portions overlying in part, and joined or bonded at least substantially on a line along the length of the strip and substantially along one edge of one strip (typically the opaque). In another embodiment, each composite strip does not include the sheer translucent portion. As manufactured, strip portions are flat and overlaid, enabling rolling up of the composite. At final fabrication into a shade, cut lengths corresponding to the height (or width) of the window are assembled by bowing at least one strip (typically the opaque) and, if of the unequal transverse width type, adhering the previously unattached edge of that strip to the other strip, forming the bowed closed-perimeter section; and if of the insert type, either inserting the resilient strip or merely allowing the previously inserted element to re-assume its natural transverse form. The bowed strips are thereby made both torsionally-stiff and rigid against bending, although the resilient nature of the stiffening will allow bending past the limit of their elastic resistance, without permanent damage.
If used in a vertical orientation, the expanded composite strips are then hung by their top ends from an overhead rail with individual hangers (as commonly used for prior art vertical strip blinds), with attachment made to either the sheer, if present, or the opaque portions of the strips. In the preferred embodiment of the invention, the sheer portion is folded back across the opaque portion and then attached to the adjacent hanger, causing the sheer to span between adjacent opaque portions and giving the illusion of a continuous sheer curtain combined with light-controlling vanes.
If used in a horizontal application, the expanded composite strips may be assembled into conventional venetian blind ladder cord and actuator structures, with the sheer portions, if present, joined along the free edge, in either continuous or periodic points, to the adjacent strip; or they may be joined one to another with the sheers in tension between them, to provide alternate means of support and actuation (vane rotation).
It should be noted that the expanded element portion of the composite may also be made without an attached sheer, providing a lightweight, insulating, and optionally, light-diffusing replacement for conventional rigid-vane opaque vertical blinds or venetian blinds. It should also be noted that the opaque portion of each vane could be constructed of a single piece of material folded on itself, rather than from separate strips with two bond lines.
As described above, the present invention employs a novel strip construction that can provide the appearance and functions of the continuous sheer with rotatable vanes, but in a manner which requires far smaller and simpler manufacturing equipment; packages and installs much more easily; and is readily handled for cleaning or repair at minimal cost. The embodiments without sheer elements provide direct replacement for conventional solid vanes in horizontal venetians or vertical blinds, but with much lower mass and stowed bulk. The separate insert embodiments, both with and without sheers, further provide for convenient and inexpensive options in light blocking features, as the inserts can be, for instance, clear, milky, smoky, reflective, polarized, or opaque, without substantially altering the surface coloration or textures of the product, unlike conventional vertical or venetian blinds.